That should at the very least be animal cruelty, which unfortunately for minors I think is generally just a slap on the wrist, maybe some community service and a bit of juvie... Even for adults such a charge is normally only accompanied by a nice fine with possibly a few months in jail. As you said, these two are well on their way to being psychopaths, especially since animal cruelty is usually the first stepping stone to that. I personally think the punishment for such things should be much worse, but since it is "just an animal" most people don't regard its life very high, and as an animal in a misunderstood hobby it will probably get even less attention.